Catalytic polymerization can be used to upgrade light olefins into gasolines of relatively high octane values and low vapor pressure providing an attractive process addition to a refinery. For example, low boiling olefins such as those containing from 3 to 5 carbon atoms per molecule can be effectively polymerized in the presence of various catalysts to produce copolymers, dimers, trimers, tetramers, etc. If desired, the products of such a polymerization can be hydrogenated to produce diesel fuels. It is also known to react isoolefins such as present in C.sub.4 fractions and methanol in the presence of an acid catalyst to produce ethers such as methyltertiarybutyl ether, which is a known octane improver. Suitable olefinic feeds for the polymerization and etherification reaction can be obtained by dehydrogenation of C.sub.3 and C.sub.4 alkanes, respectively.
Catalytic polymerization is a highly exothermic reaction and heat removal considerations are important in order to produce desirable products. Such is the case experienced during the polymerization of low boiling olefins in the production of dimers, trimers, and tetramers. Various expedients have been attempted in an effort to control the polymerization reaction temperature. The present invention is directed to a combination process comprising polymerization and etherification for producing high quality diesel fuel and high quality gasoline from low boiling olefins wherein unreacted linear olefins recovered from the etherification reaction are used as at least part of the quench for the olefin polymerization to cool the reaction and produce additional linear olefin polymer.
Accordingly, an object of this invention is to produce high quality diesel fuel and high quality gasoline from low boiling olefins.
Another object of this invention is to provide a combination process for the polymerization and etherification of low boiling olefins.
Another object of this invention is to control polymerization reaction temperatures.
A further object of this invention is to provide a quench stream for olefin polymerization, to cool the polymerization reaction and produce additional polymer.
Other objects, aspects, as well as the several advantages of the invention will be apparent to those skilled in the art upon consideration of the specification, the drawing, and the appended claims.